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BMW X5 E53 How To – Trailer Lighting Harness Control Module Install DIY

September 21, 2012

This DIY will show how to install the trailer lighting control module on all E53 chassis X5 models (00-06), to include; 3.0i, 4.4i, 4.6is, 4.8is.

The module is required in order to have the proper outputs to the trailer lighting harness connector plug.  The signals to the running, brake and turn lights are modulated and the trailer lighting module must be installed so that the harness plug will output the proper signals to the trailer lighting harness.


1)  Remove the cargo floor.

2)  Remove the spare tire.  NOTE; the proper procedure for removing the spare tire is shown on the instructions on the underside of the cargo floor panel.

3)  Remove the spare tire mount assembly.  Remove the two 13mm bolts and two 13mm nuts, then lift out the mount assembly.

NOTE; models with self-leveling rear suspension will have the suspension air pump mounted in this location.  Remove the four 13mm bolts on the mounting bracket arms and move the bracket and pump assembly aside.

4)  Remove the electric box cover.  Remove the three Phillips-head screws and lift out the cover.

5)  Remove the harness carrier.  Remove three Phillips-head screws and loosen one.  Lift out the carrier.

6)  Locate the trailer lighting control module harness plug.

7)  Unlock the harness plug locking clamp and install the module to the harness plug.  Slide the locking clamp while pushing the harness plug securely on to the module.

8)  Mount the module to the harness carrier, between the securing clips.

9)  Reassemble.

The trailer lighting harness plug (mounted to the rear panel, passenger side, below the tailgate opening) is now active and ready for use.

The BMW trailer wiring kit, includes the module and the  harness plug assembly that is designed to neatly plug into this vehicle harness plug and route through the tail-panel (through a pre-cut access hole, which has a sealing grommet in place) to the towing hitch assembly, providing a fully powered 7-pin round trailer connector plug.  The BMW trailer wiring kit also includes a 7-pin round to 4-pin flat converter.

Click below for BMW E53 X5 trailer lighting kit:

Click below for BMW E53 X5 trailer hitch:

Bavarian Autosport

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